Compact modular liquid cooling systems for electronics

ABSTRACT

A cooling system for a microchip or other component is described, including, in one embodiment: (1) a cold plate assembly positioned adjacent (e.g., in contact with) the component to be cooled; (2) at least one heat exchanger; (3) a fan for directing gas adjacent (e.g., through) a portion of the heat exchanger; and (4) a pump for circulating cooling fluid through a closed circuit including the cold plate and heat exchanger. The cold plate may include guide fins that define macrochannels and microchannels that serve as conduits for the cooling fluid. The fins and channels in one embodiment are shaped to substantially match the heat map profile of the chip or component to be cooled. The heat exchanger in one embodiment includes a reservoir in its base which may cooperate with a recess or channel in a support plate to form an additional cooling fluid flow passage.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 61/310,384, entitled Integrated, Modular, Multi-Scale Liquid Cooling System for Electronics Thermal Management, filed Mar. 4, 2010, which is hereby incorporated herein by reference in its entirety.

BACKGROUND

Electronic components including microchips and microprocessors generate large amounts of heat relative to their size during normal operation. As processor speed increases, a related increase in heat energy represents a serious challenge to progress, especially as devices get smaller and components get more densely packed together. The ability to dissipate heat energy is becoming a critical design constraint for all types of electronic devices. Existing systems fail to provide satisfactory cooling performance and represent a serious limiting factor on the overall speed and performance of electronic devices.

SUMMARY

A cooling system for electronic components (or other objects), according to various embodiments, comprises: (1) a cold plate assembly defining at least one cold plate fluid flow passage, the cold plate defining an upper and a lower surface; (2) at least one heat exchanger disposed adjacent the upper surface of the cold plate assembly, each of the at least one heat exchangers comprising at least one heat exchanger fluid flow passage; (3) a fan that is positioned for causing gas to flow adjacent the heat exchanger; (4) one or more liquid conduits for facilitating the flow of a cooling fluid through an at least substantially closed circuit that extends through the cold plate fluid flow passage and the at least one heat exchanger fluid flow passage; and (5) a pump that is positioned and configured to cause the cooling fluid to flow through the substantially closed circuit. In particular embodiments: (1) the cold plate assembly comprises: (A) a cold plate; and (B) a support plate disposed immediately adjacent the upper surface of the cold plate; (2) a perimeter of the support plate is longer than a perimeter of the cold plate; and (3) the cooling system is adapted to be positioned adjacent an electronic component and to cool the electronic component.

A cooling system for electronic components (or other items) according to further embodiments comprises: (1) a cold plate assembly defining at least one cold plate fluid flow passage, the cold plate assembly defining an upper and a lower surface; (2) at least one heat exchanger defining at least one heat exchanger fluid flow passage; (3) a fan positioned to cause gas to flow adjacent the heat exchanger; (4) one or more liquid conduits for facilitating the flow of a cooling fluid through an at least substantially closed circuit that extends through the cold plate fluid flow passage and the at least one heat exchanger fluid flow passage; and (5) a pump that is positioned and configured to cause the cooling fluid to flow through the at least substantially closed circuit. In particular embodiments, (1) the cooling system is adapted to be positioned so that the cold plate assembly engages an electronic component to thereby cool the electronic component; (2) a lower portion of the heat exchanger and a particular portion of the upper surface of the cold plate assembly cooperate to form a fluid reservoir; and (3) the cooling system is adapted so that, as cooling fluid flows through the at least substantially closed liquid circuit: (A) at least a portion of the cooling fluid flows through the fluid reservoir; and (B) as a volume of the cooling fluid flows through the fluid reservoir, the volume of the cooling fluid engages both an interior surface of the lower portion of the heat exchanger and the particular portion of the upper surface of the cold plate assembly.

A method of cooling an electronic component, according to various embodiments, comprises: (1) providing a cold plate assembly that defines at least one cold plate fluid flow passage and that includes a plurality of fins that are disposed within the fluid flow passage; (2) providing at least one heat exchanger that defines at least one heat exchanger fluid flow passage; (3) providing a fan that is positioned to cause gas to flow adjacent the at least one heat exchanger; (4) providing a pump that is adapted for circulating a cooling fluid first through the at least one heat exchanger fluid flow passage and then through the at least one cold plate fluid flow passage; (5) using the pump to repeatedly recirculate the cooling fluid first through the at least one heat exchanger fluid flow passage and then through the at least one cold plate fluid flow passage; (6) while executing Step (5) above, using the fan to cause gas to flow adjacent the at least one heat exchanger; and (7) using the cold plate assembly to cool the electronic component.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described various embodiments in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 is a perspective view of a cooling system according to a particular embodiment.

FIG. 2 is a plan view of the cooling system of FIG. 1.

FIG. 3 is a perspective view of a cooling system according to a further embodiment.

FIG. 4 is a perspective view of a cooling system according to another embodiment.

FIG. 5 is a plan view of the cooling system of FIG. 4.

FIG. 6 is a perspective view of a cooling system according to a further embodiment.

FIG. 7 is a perspective top view of a cooling system according to another embodiment.

FIG. 8 is a plan view of a cooling system according to a further embodiment.

FIG. 9 is a perspective view of a cold plate according to a particular embodiment.

FIG. 10 is a perspective view of a cold plate according to a further embodiment.

FIG. 11 is a perspective view of a cold plate according to yet another embodiment.

FIG. 12 is a perspective view of a cold plate according to a further embodiment.

FIG. 13A is a perspective top side view of a heat exchanger according to a particular embodiments.

FIG. 13B is a perspective bottom side view of the heat exchanger of FIG. 13A.

FIG. 14 is a top perspective view of the cold plate assembly of that includes the cold plate of FIG. 12 and multiple heat exchangers of the type shown in FIGS. 13A and 13B.

FIG. 15A is a perspective view of a cooling system according to a particular embodiment.

FIG. 15B is a perspective view of a cooling system according to a further embodiment.

FIG. 15C is a plan view of the cooling system of FIG. 15B.

FIG. 15D is a side view of the cooling system of FIG. 15B.

FIG. 15E is a perspective bottom view of the cooling system of FIG. 15B.

FIG. 16 is a top perspective view of a cold plate assembly according to particular embodiments.

FIG. 17A is a perspective view of a heat exchanger in a cooling system according a particular embodiment.

FIG. 17B is a side perspective view of the heat exchanger of FIG. 17A.

FIG. 17C is a perspective view of a cooling system that includes the cold plate assembly of FIG. 16 and the heat exchanger of FIG. 17A.

FIG. 17D is a perspective view of the cooling system of FIG. 17C.

DETAILED DESCRIPTION

Various embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

Various embodiments of the invention are directed toward systems and methods of cooling small heat-producing devices, including electronic components such as microchips. Removing or dissipating the heat energy away from electronic components may facilitate better speed and performance and reduce the number and severity of failure events. Although several embodiments are discussed with reference to cooling a microchip, the invention may be applied to any of a variety of other heat-producing devices that may benefit from cooling.

In one embodiment, a cooling system may include a volume of cooling fluid and a cold plate positioned near a microchip or other object to be cooled, a pump for circulating the cooling fluid through conduits in the system, one or more heat exchangers to cool the fluid, a fan to circulate gas (such as air or an inert gas) adjacent the heat exchangers, and a support plate for supporting the system's various components. Liquid water, with or without additives, or any other suitable cooling fluid, may be used as a cooling fluid within the context of the cooling system. Any of a variety of types of heat exchangers may be used, separately or in combination, in series or parallel, and using any type of flow arrangement. Examples of these components are described below in various implementations.

Exemplary Cooling System

As shown in FIGS. 1 and 2, a cooling system 10 according to a particular embodiment comprises: (1) a cold plate 100; (2) a support plate 200 that is attached adjacent (e.g., to) an upper surface of said cold plate 100; (3) a fan 500A that is attached adjacent (e.g., to) an upper surface of said support plate 200; (4) a pump 300 that is attached adjacent (e.g., to) an upper surface of said support plate 200; and (5) a series of heat exchanges 400A, 400B, 400C. The cooling system 10 further includes tubing 600 that is adapted to direct the flow of a cooling fluid through a circuit (e.g., a substantially closed circuit) that extends through the cold plate 100, the series of heat exchangers 400A, 400B, 400C, and the pump 300. In particular embodiments, the pump is adapted to cause the cooling fluid to flow, in a recirculating manner, through the closed loop.

Cold Plate

As noted above, in particular embodiments, the cooling system 10 includes a cold plate 100 for cooling objects that are positioned adjacent (e.g., so that they are engaging) the cold plate 100. In particular embodiments, the cold plate 100 is in the form of a substantially planar, rectangular parallelogram and defines a cold plate inlet 110, a cold plate outlet 115, and a substantially fluid-tight cold plate fluid flow passage 120 that extends from the cold plate cold plate inlet 110 to the cold plate outlet 115. In particular embodiments, the cold plate 100 includes a lid that is adapted to maintain the substantially fluid-tight nature of the fluid flow passage 120.

In particular embodiments, the cold plate is made of a highly thermally conductive metal, such as copper. However, in other embodiments, the cold plate 100 may be made of any other suitable material.

An exemplary cold plate 100 is shown in FIG. 9. In this embodiment, the fluid flow passage 120 includes an entry portion 130 adjacent the cold plate inlet 110, an exit portion 165 adjacent the cold plate outlet 115, and a central portion 145 that extends between the entry portion 130 and the exit portion 165. The entry portion 130 is substantially triangular and includes a set of radially extending fins 135 that extend outwardly from a position that is adjacent the cold plate inlet 110. These fins 135 cooperate to form a plurality of macrochannels 175 that expand in width from their inlet end to their outlet end. The central portion 145 is substantially rectangular and includes a set of substantially parallel guide fins 150 that are positioned to define a series of microchannels 160 between the guide fins 150. The exit portion 165 is substantially triangular and includes plurality of radially extending fins 170 that extend outwardly from a position that is adjacent the cold plate inlet 110. These fins 170 cooperate to form a plurality of macrochannels 175 that decrease in width from their inlet end to their outlet end.

In the above configuration, the cold plate 100 is adapted to direct a cooling fluid from the cold plate's inlet 110, through the fluid flow passage's entry portion 130, through the microchannels 160 defined by the substantially parallel set of guide fins 150, through the fluid flow passage's exit portion 165 and out of the cold plate's outlet 115. As discussed in greater detail below, during this process, the cooling fluid engages the various guide fins 135, 150, 170 and thereby removes heat from the guide fins). This allows the cold plate 100 to absorb heat from objects that are adjacent and/or in contact with, the cold plate 100.

As may be understood from FIGS. 10 and 11, an alternative embodiment of the cold plate 100 may include many different configurations of fins for absorbing heat from liquid passing through the cold plate 100. For example, as shown in FIG. 10, in an alternative embodiment, a plurality of substantially uniformly spaced pin fins 150 is provided in the cold plate's fluid flow passage 120. In this embodiment, the pin fins 150 cooperate to define a plurality of circuitous passages through which the cooling fluid flows as it passes through the cold plate's fluid flow passage 120. During this process, the cooling fluid contacts the pin fins 150 and thereby absorbs heat from the pin fins 150, which serves to cool the cold plate's exterior.

As shown in FIG. 10, in particular embodiments, the plurality of pin fins 150 may be distributed over at least about 40%, at least about 50%, at least about 60%, at least about 70%, or at least about 80% of the surface area of the bottom of the cold plate's fluid flow passage 120.

As may be understood from FIG. 11, the cold plate 100 may include fins of a variety of different shapes and sizes. For example, the fins may be straight or curved, parallel or angled, arrayed or random, full depth or partial, smooth or textured, continuous or interrupted, any combination, or any other size or shape that facilitates a desired flow pattern and a desired heat transfer.

In various embodiments, the guide fins are configured and spaced according to the needs indicated by a heat map of an object (e.g., a computer chip or other electrical component) to be cooled by the cold plate 100. For example, a tighter cluster of pin fins may be provided adjacent a portion of the object that has been determined, through heat mapping techniques, to be particularly hot.

Support Plate

As discussed above, the cooling system 10 may include a support plate 200, that is attached adjacent (e.g., to) a surface (e.g., an upper surface) of the cold plate 100, and that is adapted for supporting one or more of the cooling system's other components. As shown in FIG. 2 and described here, the cold plate 100 may be attached adjacent (e.g., to) the center of the support plate's bottom surface.

In various embodiments, the support plate 200: (1) is made of a highly thermally conductive material (e.g., a highly thermally conductive metal such as copper, or other suitable material); (2) is substantially planar; (3) is relatively thin; (4) and has a footprint that is larger than a footprint of the cold plate 100 (e.g., the perimeter of the support plate 200 may be at least about 40%, at least about 50%, or at least about 60% larger than the perimeter of the cold plate 100). This may allow the support plate 200 to serve the duel functions of supporting certain cooling system components and dissipating heat from the cold plate.

The support plate 200 (as well as the other components) may be sized and shaped to fit within any of a variety of spaces. For example, the support plate 200 in one embodiment may be substantially square in shape and measure 75 millimeters along one side.

Heat Exchangers

As shown in FIGS. 1 and 2, the cooling system 10 may include a plurality of heat exchangers (in this example three radiators 400A, 400B, and 400C) that are attached in series. In this embodiment, each heat exchanger 400A, 400B, and 400C includes a heat exchanger inlet 405, a heat exchanger outlet 410, a heat exchanger fluid flow passage 415 (e.g., a winding tube), and a plurality of fins that serve to dissipate heat from a cooling liquid as the cooling liquid flows through the fluid flow passage 415.

Although plate and frame heat exchangers are shown and described in various embodiments, any suitable type or number of heat exchangers may be used, in series or parallel, using any suitable type of flow arrangement. Although various heat exchangers are described herein as using single-phase liquid water, either single-phase or phase-change heat exchangers may be appropriate for certain applications.

Fan

As noted above, the cooling system 10 shown in FIGS. 1 and 2 comprises a fan 500A positioned on the upper surface 205 of the support plate 200 and in a central location relative to the cooling system's other components. The fan 500A (or other type of air mover) is positioned to produce a current of gas (or other fluid) adjacent the heat exchangers 400A, 400B, 400C to dissipate heat from adjacent the heat exchangers 400A, 400B, 400C. This increases the effectiveness of the heat exchangers 400A, 400B, 400C.

Although the fan 500A shown in FIGS. 1 and 2 includes as a series of fan blades 505 mounted on a central rotating shaft, in other embodiments, the fan may be any type of device capable of producing a flow (e.g., a steady flow) of gas. Size, geometry of nearby components, and optimization of heat transfer are some of the constraints that may influence the selection of a fan for a particular embodiment.

Pump and Tubing

As shown in FIGS. 1 and 2, a pump 300 may be mounted adjacent (e.g., to) the support plate 200. In various embodiments, this pump 300 is positioned and configured to cause a cooling fluid to flow through a substantially closed circuit (or alternatively another type of circuit) that extends through the cold plate's fluid flow passage 120 and through the heat exchangers' respective fluid flow passages 415. The pump 300 may be any of a variety of suitable types of pumps, such as a rotary pump, piston pump, displacement pump, centrifugal pump, and the like. As shown in FIG. 5, a pump 300 may include an inlet 305 and an outlet 310. In one aspect, the pump 300 and piping or tubing 600 may be sized in relation to one another for the efficient and cooperative generation of a fluid flow through the cooling system 10.

As shown in FIG. 2, the cooling system may provide tubing 600 or any other suitable materials for providing a conduit for cooling liquid as the cooling liquid travels between the cooling system's various components. In this embodiment, the tubing 600 (together with the system's components) provides a substantially closed circuit for the cooling fluid. The tubing 600 may be copper or any other suitable material and may be insulated or bare along particular sections, depending on the desired heat transfer for that section of tubing 600.

Operation of the First Embodiment

When the cooling system embodiment described above is in operation, the component to be cooled (e.g., a computer chip or other electric component) is positioned adjacent the cold plate 100 so that, for example, the component is in physical contact with the cold plate 100. While the component is positioned adjacent the cold plate 100, the pump 300 repeatedly circulates a cooling fluid through an at least substantially closed circuit that extends through the cold plate's fluid flow passage 120 and the heat exchangers' respective fluid flow passages 415. This serves to cool the component.

More particularly, after the cooling fluid passes through the cold plate's fluid flow passage 120 and absorbs heat from the computer chip 50 or other component as described above, the cooling fluid exits the cold plate 100 through the cold plate's outlet 115 as shown in FIG. 2. The cooling fluid then: (1) flows, via a suitable conduit 600, to the inlet 405A of a first heat exchanger 400A; (2) passes through the first heat exchanger 400A; and (3) exits the first heat exchanger 400A through the first heat exchanger's outlet 410A. The cooling fluid then repeats this process for the system's other heat exchangers 400B, 400C. As the cooling fluid flows through the heat cooling system's heat exchangers 400A, 400B, 400C, the fan 500 directs a flow of air (or any other suitable gas) adjacent the heat exchangers 400A, 400B, 400C. This dissipates heat from adjacent the heat exchangers 400A, 400B, 400C, which improves the performance of the heat exchangers as the heat exchangers 400A, 400B, 400C cool the cooling liquid.

After being cooled by the cooling system's heat exchangers 400A, 400B, 400C, the fluid may be driven by a pump 300 toward the cold plate's inlet 110 and into the cold plate 100, as shown in FIG. 2. The cooled fluid may then flow, as described above, through the cold plate's fluid flow passage 120 until it reaches the cold plate's outlet 115, where the circulation described in this example begins again. This process may repeat over an extended period of time.

Alternate Fan Locations and Heat Exchanger Arrangements

The fan may be located and positioned in any way that facilitates a beneficial flow of gas around the heat exchangers, pump, fan housing, and/or other components of the system, as well as nearby components or structures in the vicinity. FIGS. 1-2 depict a cooling system 10 comprising a series of heat exchangers 400A, 400B, 400C disposed near three sides of a support plate 200 and partially surrounding a fan 500A. FIG. 3 depicts a similar cooling system 10 comprising a fan 500B centrally located but positioned higher above the support plate 200 than the fan 500A depicted in FIG. 1.

Similarly, FIGS. 4-5 depict a cooling system 10 comprising a heat exchanger 400D partially surrounding a fan 500C. FIG. 6 depicts a similar cooling system 10 comprising a fan 500D centrally located but positioned higher above the support plate 200 than the fan 500C depicted in FIG. 4. The heat exchanger 400D depicted in FIGS. 4-5 is substantially semi-circular in overall shape, having a series of plates and fins 460D in the embodiment shown. For designs having a more compact footprint, the support plate 200 may be shaped more like the semi-circular heat exchanger 400D. Alternatively, depending on the particular application and the desired heat transfer properties, the support plate 200 may be shaped as shown, exposing more surface area to the ambient surrounding and promoting radiant heat transfer.

FIGS. 7-8 depict a cooling system 10 comprising at least two heat exchangers 400E, 400F partially surrounding a fan 500E. The heat exchangers 400E, 400F are substantially rectangular in overall shape, having a series of plates and fins 460E in the embodiment shown. In these figures, the fan 500E as shown may be centrally positioned on an axis substantially parallel to the upper surface 205 of the support plate 200. In this configuration, the fan 500E can produce a flow that draws gas through one heat exchanger and pushes gas through the other. In another aspect, as shown in FIG. 8, the substantially central position of the fan 500E may assist in cooling the upper surface 205 of the support plate 200 as well as the cold plate assembly 100 beneath. The pipes 600 also may benefit from a flow of gas produced by the fan 500E.

A cold plate assembly 100 according to various embodiments is depicted, in plan view, in FIGS. 2, 5, and 8. In one aspect of these embodiments, the central portion 106 of the cold plate's bottom surface may be located and sized to generally match the size and location of the chip 50 to be cooled. In use, the cooling system 10 may be located such that the central portion 106 of the cold plate's bottom surface is at least in partial contact with the chip 50 to be cooled.

As depicted in FIGS. 9-11, the central portion 145 of the cold plate fluid flow passage may include one or more guide fins 135, 150, 170, macro-channels 140, 175, and micro-channels 160. FIG. 9 depicts guide fins 135, 150, 170 that are elongated and shaped like miniature walls. FIG. 11 depicts guide fins of various shapes, including elongated guide fins of varying height 135, 170 and other irregular shapes. In contrast, FIG. 10 depicts no guide fins in the entry portion 130 or the exit portion 165 of the cold plate's fluid flow passage. In this and other embodiments, the cold plate assembly 100 may include one or more inlets near the entry portion 130 and one or more outlets near the exit portion 165 of the cold plate fluid flow passage. The second set of guide fins 150 in FIG. 10 comprises an array of pin-shaped cylinders sometimes called pin fins. In one aspect, the configuration of a cold plate 100 and its guide fins for a particular application depends on a variety of design constraints and thermal performance needs. For example, a steady or laminar flow of cooling fluid may be desired for certain applications, while a rapid or turbulent flow may perform better for other applications. Different configurations of flow speeds, inlets and outlets, passage shapes, guide fins, channel shapes, wall textures, and other features may come to mind to those skilled in the art who have the benefit of the teachings presented herein and the embodiments disclosed.

Second Embodiment

A cooling system according to a second embodiment may include at least one heat exchanger that is adapted to facilitate the flow of cooling fluid over a portion of the cold plate's upper surface. An example of such a heat exchanger 400G is shown in FIGS. 13A-13B. As may be understood from these figures, the heat exchanger 400G comprises a thin, elongated heat exchanger fluid flow passage 415. As shown, the heat exchanger 400G includes a plurality of fins positioned partially between sections of the flow passage 415. The heat exchanger 400G also includes a base 440 that forms both a structural footing for the heat exchanger and a space beneath for a fluid reservoir 420. In this embodiment, the fluid flow passage 415 conveys cooling fluid first into a heat exchanger outlet 405G, then makes several passes back and forth through the main body of the heat exchanger 440G, then through an opening at a first end 445 of the base 440, into and through the fluid reservoir 420, then up through an outlet at a second end 450, and then out through the heat exchanger outlet 410G.

FIG. 12 depicts a cold plate 100 that is particularly suitable for this type of implementation. In this embodiment, the cold plate upper surface 102 comprises a plurality of substantially rectangular recesses sized and shaped for receiving the base 440 of a heat exchanger 440G like the one depicted in FIGS. 13A-13B. In FIG. 12, the recesses are at least partially surrounded, respectively, by a heat exchanger O-ring 430G, 430H, 430I, 430J. The central portion 190 of the cold plate 100 includes a lid 185 as shown in FIG. 12.

FIG. 14 shows an embodiment in which the respective bases of a plurality of heat exchangers 400G, 400H, 400I, 400J are positioned adjacent the recesses in the cold plate 100. When in place, the recesses in the cold plate upper surface 102 cooperate with the fluid reservoirs 420 to form a chamber inside the base of each heat exchanger. This chamber forms part of the heat exchanger's fluid flow path 415. Referring again to FIGS. 13A-13B, the base 440 of heat exchanger 400G may be positioned adjacent or mounted on its corresponding O-ring 430G (FIG. 12). When in place, the fluid reservoir 420 in the base 440 cooperates with the substantially rectangular recess in the upper surface 102 to form a chamber underneath the heat exchanger 400G; that chamber forms part of the heat exchanger flow path 415. In this aspect, the heat exchanger 440G in this embodiment facilitates the flow of cooling fluid across the upper surface 102 of the cold plate 100, which may, in various embodiment, help to cool the cold plate 100.

Full Cooling System According to Second Embodiment

FIG. 14 depicts, within the context of a cooling system according to a second embodiment, only the cold plate assembly 100 and the general arrangement of heat exchangers 400G-J without other system components such as a fan, a pump, or tubing.

FIG. 15A depicts a cooling system according to the second embodiment, which includes similar aspects to those described above with reference to FIGS. 12-14. In FIG. 15A, the cooling system includes a fan 500F, a pump 300, and tubing 600 connecting the system's various components, including the heat exchangers 400K, 400L, 400M, 400N. Like the upper surface 102 of the cold plate depicted in FIG. 12, the upper surface of the cold plate depicted in FIG. 15A includes at least one substantially rectangular recess. Like the base 440 and fluid reservoir 420 of the heat exchanger 400G depicted in FIG. 13B, at least one of the heat exchangers depicted in FIG. 15A includes a fluid reservoir in its base. In this aspect, the cooling system depicted in FIG. 15A is adapted to facilitate the flow of cooling fluid through a heat exchanger fluid flow passage and through a cold plate fluid flow passage.

In the cooling system depicted in FIG. 15A, at least one of the heat exchangers includes a space beneath its base, creating a fluid reservoir 420 (shown in FIG. 13B). The upper surface of the cold plate assembly depicted in FIG. 15A comprises at least one substantially rectangular recess that is sized and shaped for receiving the base of a heat exchanger. The substantially rectangular recess in the upper surface forms part of a cold plate fluid flow passage. When the base of the heat exchanger is placed or mounted adjacent the rectangular recess, the fluid reservoir 420 cooperates with the rectangular recess in the upper surface 102, forming a chamber inside the base of each heat exchanger. In this aspect, the chamber becomes part of the heat exchanger flow path 415 (FIG. 13A) as described above.

FIG. 15B depicts the cooling system of FIG. 15A, with an additional upper heat exchanger 400X mounted in a plan substantially parallel to the cold plate assembly. FIG. 15C is a top view depicting a cooling system that includes the upper heat exchanger 400X. FIG. 15D is a side view depicting the arrangement of a pump 300, tubing, other heat exchangers, and the upper heat exchanger 400X.

FIG. 15E depicts cooling system that includes the upper heat exchanger 400X. As shown, cold plate assembly 100 in this embodiment includes a bottom surface. In this configuration, the cold plate assembly 100 may be configured and positioned so that at least part of the bottom surface's central portion 106 is in contact with a microchip or other heat-producing component.

Fluid Flow Passages and Heat Transfer—Second Embodiment

As in the first embodiment, the flow of cooling liquid through the cold plate assembly 100 absorbs heat from the chip 50 or other component. Referring to FIG. 15A, the cooling fluid may be driven by a pump 300 along a flow path inside the pipes or tubing 600, toward and through heat exchangers 400L, 400M, 400N, 400K. As described above, the cooling fluid not only flows through the main fluid flow passage inside the body of the heat exchanger, but it also flows through a chamber in the base of the heat exchanger where the cooling fluid also comes in contact with the upper surface of the cold plate assembly 100. This interaction with the cold plate assembly 100 may improve the cooling of the cold plate assembly 100.

The flow of gas produced by natural convection and by the fan 500F around the heat exchangers promotes heat transfer, further cooling the fluid. Heat transfer may be aided by a heat exchanger made of copper or other conducting material, or a heat exchanger with fins or other shapes and features to promote radiant heat transfer.

After being cooled through one or more heat exchangers, the fluid may be driven by a pump 300 toward a central portion 190 (FIG. 12) of the cold plate assembly 100. The cooled fluid may flow across and through the interior of a central portion 190 of the cold plate 100 and then return to the pump 300, where the circulation described in this example may begin again. The central portion 190 of the cold plate may be positioned underneath the main body or platform of the cold plate assembly 100, as depicted in FIG. 15E. Like the cold plates shown in FIGS. 9-11, the cold plate assembly 100 shown in FIG. 15E may include a cold plate fluid flow passage having an entry portion, a central portion, and an exit portion. As depicted in FIGS. 9-11, the central portion 145 of the cold plate fluid flow passage may include one or more guide fins, macro-channels, and micro-channels. In one embodiment, this central portion 145 inside the cold plate assembly 100 may substantially coincide in size and shape with the bottom surface 106 of the cold plate assembly as shown in FIG. 15E. When in place, the cooling system 10 may be positioned such that at least a portion of the bottom surface 106 of the cold plate assembly 100 is in contact with the chip 50 or other heat-producing component. The flow of cooling fluid across and through the cold plate assembly 100 helps cool the bottom surface 106 and thereby helps absorb heat energy from the chip 50.

Third Embodiment

A cooling system according to a third embodiment may include at least one heat exchanger that is adapted to facilitate the flow of cooling fluid over a portion of the cold plate's upper surface. An example of such a heat exchanger 400R and the cold plate assembly 100 with which it cooperates, is depicted in FIGS. 16 and 17A-D. As may be understood from FIG. 17A, the heat exchanger 400R comprises a base 440, a central portion 455, and an elongated heat exchanger fluid flow passage 435 that has a substantially semi-circular overall shape. The central portion 455 may coincide in size and shape, in one embodiment, with the central portion 190 of the cold plate assembly 100 shown in FIG. 16. As depicted in FIG. 17B, the heat exchanger base 440 acts as a structural footing for the heat exchanger and creates a space beneath the base 440 for a fluid reservoir. As shown in FIG. 17B, this fluid reservoir is part of the heat exchanger fluid flow passage 435 by way of an inlet 405 and outlet 410 in the base 440. In this aspect, the heat exchanger 440R in this embodiment facilitates the flow of cooling fluid across the upper surface 102 of the cold plate 100.

FIG. 16 depicts a cold plate assembly 100 that is particularly suitable for this semi-circular embodiment. In this embodiment, the cold plate upper surface 102 comprises a semi-continuous fin channel 195 that is substantially semi-circular in overall shape. The fin channel 195 may be sized and shaped for receiving the base 440 of a heat exchanger 440R like the one depicted in FIGS. 17A-B. In particular embodiments, the shape of the perimeter of the fin channel 195 at least generally corresponds to the shape of the perimeter of the heat exchanger's base 440R. The fin channel 195 may also include passages separate from and not covered by the base of any heat exchanger. In FIG. 16, the recesses are at least partially surrounded by a peripheral channel or seat for receiving a sealing member or cold plate O-ring 180. The fin channel 195 forms part of a cold plate fluid flow passage which, in this embodiment, facilitates fluid flow across a portion of the upper surface 102 of the cold plate assembly 100.

Like the central portion 145 of the cold plate fluid flow passage depicted in FIGS. 9-11, the fin channel 195 in this embodiment may include any number and variety of guide fins or other features, creating macro-channels and micro-channels, or no features at all. The fin channel 195 depicted in FIG. 16 includes a plurality of pin fins. In one aspect, the pin fins serve as a plurality of interrupted guide fins, creating a fluid flow around and between the pin fins. The pin fins may be made of copper or other conducting material which, in one aspect, may help facilitate heat transfer and aid cooling of the cold plate assembly 100, the other components, and the fluid.

Cooling System According to Third Embodiment

FIG. 17C depicts a cooling system according to the third embodiment. As shown, the cooling system comprises a fan 500R, a pump 300R, a heat exchanger 400R, and pipes or tubing connecting the various components. Like the upper surface 102 of the cold plate depicted in FIG. 16, the upper surface of the cold plate depicted in FIG. 17C includes at least one fin channel 195. Like the base 440 and fluid reservoir of heat exchanger 400R depicted in FIG. 17B, the heat exchanger 400R depicted in FIG. 17C includes a fluid reservoir in its base 440. When the base 440 of the heat exchanger 400R is placed or mounted adjacent the fin channel 195, the fluid reservoir cooperates with the fin channel 195 to form a chamber inside the base of each heat exchanger. In this aspect, the chamber becomes part of both the heat exchanger flow passage 435 and the cold plate fluid flow passage. In this way, the cooling system depicted in FIG. 17C is adapted to facilitate the flow of cooling fluid through a heat exchanger fluid flow passage 435 and through a cold plate fluid flow passage which, in this embodiment, comprises a fin channel 195 on a portion of the upper surface 102 of the cold plate assembly 100.

Fluid Flow Passages and Heat Transfer—Third Embodiment

In this third embodiment, the flow of cooling liquid across and through the cold plate assembly 100 absorbs heat from the chip 50 or other component. Referring to FIG. 17C, the cooling fluid may be driven by a pump 300R along a heat exchanger flow path 435 (FIG. 17A) through the heat exchanger 400R. As described above the cooling fluid not only flows through the main fluid flow passage inside the body of the heat exchanger 400R, but it also flows through a chamber in the base 440 of the heat exchanger 400R where the cooling fluid also comes in contact with the upper surface 102 of the cold plate assembly 100. This interaction with the cold plate assembly 100 may improve the cooling of the fluid, the cooling of the cold plate assembly 100, or both. The flow of gas produced by natural convection and by the fan 500R around the heat exchanger 400R promotes heat transfer, further cooling the fluid. Heat transfer may be aided by a heat exchanger made of copper or other conducting material, or a heat exchanger with fins 460R or other shapes and features to promote radiant heat transfer.

Referring to FIG. 17C, the cooling fluid may be driven by a pump 300R into the upper opening of the heat exchanger 400R. As shown, after passing through the heat exchanger 400R, the fluid may exit through the lower opening of the heat exchanger 400R and then pass downward through inlet 410 (shown in FIG. 17B) and into the fin channel 195 of the cold plate assembly 100. The cooled fluid may flow across and through the fin channel 195, entering the central portion 190 of the cold plate assembly 100 and continuing the circuit to outlet 405 (shown in FIG. 17B) and returning to the pump 300R, where the circulation described in this example may begin again.

In one embodiment, the cooling system may be positioned such that at least a portion of the bottom surface of the central portion 190 of the cold plate assembly (which, in this example, is simply a cold plate) is contact with the microchip or other heat-producing component. The flow of cooling fluid through the fin channel 195, including the central portion 190, helps cool the corresponding bottom surface and thereby helps absorb heat energy from the chip 50. As shown in FIG. 17D, the cold plate assembly 100 in this embodiment includes a bottom surface. In one embodiment, the central portion 190 (shown in FIG. 16) may substantially coincide with the bottom surface's central portion 106 (shown in FIG. 17D). In the configuration shown in FIG. 17D, the cold plate assembly 100 may be configured and positioned so that at least part of the bottom surface's central portion 106 is in contact with a microchip or other heat-producing component.

CONCLUSION

Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. For example, as will be understood by one skilled in the relevant field in light of this disclosure, the invention may take form in a variety of different mechanical and operational configurations. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for the purposes of limitation. 

1. A cooling system for electronic components comprising: a cold plate assembly defining at least one cold plate fluid flow passage, said cold plate defining an upper and a lower surface; at least one heat exchanger disposed adjacent said upper surface of said cold plate assembly, each of said at least one heat exchangers comprising at least one heat exchanger fluid flow passage; a fan that is positioned for causing gas to flow adjacent said heat exchanger; one or more liquid conduits for facilitating the flow of a cooling fluid through an at least substantially closed circuit that extends through said cold plate fluid flow passage and said at least one heat exchanger fluid flow passage; and a pump that is positioned and configured to cause said cooling fluid to flow through said substantially closed circuit, wherein: said cold plate assembly comprises: (A) a cold plate; and (B) a support plate disposed immediately adjacent said upper surface of said cold plate, wherein a perimeter of said support plate is longer than a perimeter of said cold plate; and said cooling system is adapted to be positioned adjacent an electronic component and to cool said electronic component.
 2. The cooling system of claim 1, wherein said pump is positioned adjacent said upper surface of said cold plate assembly.
 3. The cooling system of claim 1, wherein said heat exchanger is at least substantially semi-annular.
 4. The cooling system of claim 1, wherein: said cold plate comprises a plurality of fins that define a plurality of microchannels; and said cooling system is adapted so that, as cooling fluid flows through said closed liquid circuit, at least a portion of said cooling fluid flows through said plurality of microchannels.
 5. The cooling system of claim 1, wherein: said cold plate comprises a plurality of interrupted fins; and said cooling system is adapted so that, as said cooling fluid flows through said closed liquid circuit, at least a portion of said cooling fluid flows through one or more passages defined by said plurality of interrupted fins.
 6. The cooling system of claim 5, wherein: said plurality of interrupted fins comprises a plurality of pin fins.
 7. The cooling system of claim 1, wherein: said heat exchanger is mounted adjacent said support plate; a lower portion said heat exchanger and a particular portion of said upper surface of said support plate cooperate to form a fluid reservoir; and said cooling system is adapted so that, as cooling fluid flows through said closed liquid circuit: at least a portion of said cooling fluid flows through said fluid reservoir; and as a volume of said cooling fluid flows through said fluid reservoir, said volume of said cooling fluid engages both an interior surface of said lower portion of said heat exchanger and said particular portion of said upper surface of said support plate.
 8. The cooling system of claim 1, wherein said fluid reservoir is at least substantially semi-annular.
 9. A cooling system for electronic components comprising: a cold plate assembly defining at least one cold plate fluid flow passage, said cold plate assembly defining an upper and a lower surface; at least one heat exchanger defining at least one heat exchanger fluid flow passage; a fan positioned to cause gas to flow adjacent said heat exchanger; one or more liquid conduits for facilitating the flow of a cooling fluid through an at least substantially closed circuit that extends through said cold plate fluid flow passage and said at least one heat exchanger fluid flow passage; and a pump that is positioned and configured to cause said cooling fluid to flow through said at least substantially closed circuit, wherein: said cooling system is adapted to be positioned so that said cold plate assembly engages an electronic component to thereby cool said electronic component; a lower portion of said heat exchanger and a particular portion of said upper surface of said cold plate assembly cooperate to form a fluid reservoir; and said cooling system is adapted so that, as cooling fluid flows through said at least substantially closed liquid circuit: at least a portion of said cooling fluid flows through said fluid reservoir; and as a volume of said cooling fluid flows through said fluid reservoir, said volume of said cooling fluid engages both an interior surface of said lower portion of said heat exchanger and said particular portion of said upper surface of said cold plate assembly.
 10. The cooling system of claim 9, wherein said fluid reservoir is at least semi-annular.
 11. The cooling system of claim 9, wherein said lower portion of said heat exchanger defines an elongated opening that is disposed immediately adjacent said upper surface of said cold plate assembly.
 12. The cooling system of claim 11, wherein: said cold plate assembly defines an elongated recess adjacent said elongated opening that comprises at least part of said fluid reservoir; said cold plate assembly comprises a plurality of fins disposed within said elongated recess; and said cooling system is adapted so that, as cooling fluid flows through said closed liquid circuit: at least a portion of said cooling fluid flows through said fluid reservoir; and as a volume of said cooling fluid flows through said fluid reservoir, said volume of said cooling fluid flows through a plurality of channels defined by said fins.
 13. The cooling system of claim 12, wherein said plurality of fins comprises a plurality of pin fins.
 14. The cooling system of said claim 9, wherein said elongated opening is substantially annular.
 15. The cooling system of claim 9, wherein said cold plate assembly comprises an electronic component engagement portion that is adapted for engaging said electronic component while said cooling system is being used to cool said electronic component; and said electronic component engagement portion is disposed adjacent a central portion of a bottom surface of said cold plate assembly.
 16. The cooling system of claim 15, wherein said electronic component engagement portion is positioned beneath said fan.
 17. A method of cooling an electronic component comprising: (A) providing a cold plate assembly that defines at least one cold plate fluid flow passage and that includes a plurality of fins that are disposed within said fluid flow passage; (B) providing at least one heat exchanger that defines at least one heat exchanger fluid flow passage; (C) providing a fan that is positioned to cause gas to flow adjacent said at least one heat exchanger; (D) providing a pump that is adapted for circulating a cooling fluid through: (1) said at least one heat exchanger fluid flow passage; and (2) said at least one cold plate fluid flow passage; (E) using said pump to repeatedly recirculate said cooling fluid through: (1) said at least one heat exchanger fluid flow passage, and (2) said at least one cold plate fluid flow passage; (F) while executing said Step (E), using said fan to cause gas to flow adjacent said at least one heat exchanger; and (G) using said cold plate assembly to cool said electronic component.
 18. The method of claim 17, wherein said step of using said cold plate assembly to cool said electronic component comprises maintaining said electronic component in physical contact with at least a portion of said cold plate.
 19. The method of claim 17, wherein said step of using said pump to repeatedly recirculate said cooling fluid through: (A) said at least one heat exchanger fluid flow passage, and (B) said at least one cold plate fluid flow passage comprises using said pump to repeatedly recirculate said cooling fluid first through one or more channels defined by said plurality of fins.
 20. The method of claim 19, wherein said one or more channels are microchannels.
 21. The method of claim 17, wherein said plurality of fins are substantially uniformly spaced apart from each other within said cold plate fluid flow passage.
 22. The method of claim 21, wherein said plurality of fins comprises at least five fins.
 23. The method of claim 17, wherein said step of using said pump to repeatedly recirculate said cooling fluid first through said at least one heat exchanger fluid flow passage and then through said at least one cold plate fluid flow passage comprises using said pump to repeatedly recirculate said cooling fluid over an upper surface of said cold plate assembly.
 24. The method of claim 23, wherein said step of using said pump to repeatedly recirculate said cooling fluid over a portion of said upper surface of said cold plate assembly comprises using said pump to repeatedly recirculate said cooling fluid over said upper surface in at least a substantially semi-annular path. 